|B|=|A3,3A2-A3,2A1+5A2|
=|A3,3A2,2A1+5A2|
=3|A3,A2,2A1|
=6|A3,A2,A1|
=-6|A1,A2,A3|
=12
解题思路是:矩阵的任一行或任一列加上其余行或其余列的任意倍数,其值不变.但交换任意行一次,或交换任意列一次则其值乘以-1.
|B|=|A3,3A2-A3,2A1+5A2|
=|A3,3A2,2A1+5A2|
=3|A3,A2,2A1|
=6|A3,A2,A1|
=-6|A1,A2,A3|
=12
解题思路是:矩阵的任一行或任一列加上其余行或其余列的任意倍数,其值不变.但交换任意行一次,或交换任意列一次则其值乘以-1.